Hybrid cord for use as reinforcement in a belt bandage of a pneumatic vehicle tire

Abstract

The invention relates to a hybrid cord for use as a reinforcement in a belt bandage of a pneumatic vehicle tire, consisting of at least two threads with ends which are twisted together. At least one first thread is a high-modulus thread with a specified thread fineness, and another thread is a low-modulus thread, said other low-modulus thread having a lower thread fineness than the first thread. The invention is characterized in that the proportion of the high-modulus thread in the hybrid cord is 80-95 wt. %; the difference between the thread fineness of the high-modulus thread and the thread fineness of the other low-modulus thread is >800 dtex; and the elongation at break of the high-modulus thread ranges from 1%-8%, and the elongation at break of the low-modulus thread ranges from 9%-30%.

The invention claimed is: 
     
       1. A hybrid cord incorporated in a belt bandage of a pneumatic vehicle tire, the hybrid cord comprising at least a first yarn having a first end and a second yarn having a second end, wherein the first end and the second end are twisted together, and wherein the proportion of the first yarn in the hybrid cord is 80-95% by weight and an asymmetry of the first yarn and the second yarn is based on a shallow initial region of a force/elongation curve;
 wherein the first yarn is a high-modulus yarn with a specified yarn fineness based on a selected residual elevation and selected circumferential growth, wherein the second yarn being is a low-modulus yarn and having a lower yarn fineness than the first yarn, and wherein the yarn fineness of the first yarn in comparison with the yarn fineness of the second yarn is ≥1150 dtex; 
 wherein the elongation at break of the first yarn lies in a range of 1%-8% and the elongation at break of the second yarn lies in a range of 9%-30%; 
 wherein a difference of the yarn count of the high modulus yarn and the low modulus yarn is greater than 800 dtex; and 
 wherein an extreme asymmetry of the yarn fineness of the first yarn in comparison with the yarn fineness of the second yarn facilitates high speed resistance of the tire where the first yarn operates predominantly for greater elongations. 
 
     
     
       2. The hybrid cord as claimed in  claim 1 , characterized in that the elongation at break of first yarn lies in a range of 3%-6% and the elongation at break of the second yarn lies in a range of 15%-25%. 
     
     
       3. The hybrid cord as claimed in  claim 1 , wherein the hybrid cord further comprises a high-modulus yarn of the same fineness as the first yarn. 
     
     
       4. The hybrid cord as claimed in  claim 1 , wherein the proportion of the first yarn in the hybrid cord is 90-95% by weight and the difference of the yarn fineness of the first yarn in comparison with the yarn fineness of the second yarn is ≥1400 dtex. 
     
     
       5. The hybrid cord as claimed in  claim 1 , wherein the first yarn is carbon fiber, glass fiber, basalt or aromatic polyamide. 
     
     
       6. The hybrid cord as claimed in  claim 1 , wherein the second yarn is a polyamide or a polyester. 
     
     
       7. The hybrid cord as claimed in  claim 1  having a construction of aramid 1680×2+nylon 700×1, or a construction of carbon fiber 1600×2+nylon 700×1. 
     
     
       8. The hybrid cord as claimed in  claim 1  having a construction of aramid 1680×2+nylon 470×1, or a construction of carbon fiber 1600×2+nylon 470×1. 
     
     
       9. The hybrid cord as claimed in  claim 1  having a construction of aramid 1680×2+nylon 235×1 or a construction of carbon fiber 1600×2+nylon 235×1. 
     
     
       10. The hybrid cord as claimed in  claim 1  as comprised in a belt bandage that covers a belt radially on the outside of the pneumatic vehicle tire, wherein the pneumatic vehicle tire is of a radial type of construction with a multi-ply breaker belt. 
     
     
       11. A hybrid cord incorporated in a belt bandage of a pneumatic vehicle tire, the hybrid cord comprising at least a first yarn having a first end and a second yarn having a second end, wherein the first end and the second end are twisted together, and wherein the proportion of the first yarn in the hybrid cord is 90-95% by weight and an asymmetry of the first yarn and the second yarn is based on a shallow initial region of a force/elongation curve;
 wherein the first yarn is a high-modulus yarn with a specified yarn fineness, wherein the second yarn being is a low-modulus yarn and having a lower yarn fineness than the first yarn, and wherein the yarn fineness of the first yarn in comparison with the yarn fineness of the second yarn is ≥1400 dtex; and, 
 wherein the elongation at break of the first yarn lies in a range of 1%-8% and the elongation at break of the second yarn lies in a range of 9%-30%. 
 
     
     
       12. The hybrid cord as claimed in  claim 11 , characterized in that the elongation at break of first yarn lies in a range of 3%-6% and the elongation at break of the second yarn lies in a range of 15%-25%. 
     
     
       13. The hybrid cord as claimed in  claim 11 , wherein the hybrid cord further comprises a high-modulus yarn of the same fineness as the first yarn. 
     
     
       14. The hybrid cord as claimed in  claim 11 , wherein the proportion of the first yarn in the hybrid cord is 90-95% by weight and the difference of the yarn fineness of the first yarn in comparison with the yarn fineness of the second yarn is ≥1400 dtex. 
     
     
       15. The hybrid cord as claimed in  claim 11 , wherein the first yarn is carbon fiber, glass fiber, basalt or aromatic polyamide, and wherein the second yarn is a polyamide or a polyester. 
     
     
       16. The hybrid cord as claimed in  claim 11  having a construction of aramid 1680×2+nylon 700×1, or a construction of carbon fiber 1600×2+nylon 700×1. 
     
     
       17. The hybrid cord as claimed in  claim 11  having a construction of aramid 1680×2+nylon 470×1, or a construction of carbon fiber 1600×2+nylon 470×1. 
     
     
       18. The hybrid cord as claimed in  claim 11  having a construction of aramid 1680×2+nylon 235×1 or a construction of carbon fiber 1600×2+nylon 235×1. 
     
     
       19. The hybrid cord as claimed in  claim 11  as comprised in a belt bandage that covers a belt radially on the outside of the pneumatic vehicle tire, wherein the pneumatic vehicle tire is of a radial type of construction with a multi-ply breaker belt. 
     
     
       20. A hybrid cord incorporated in a belt bandage of a pneumatic vehicle tire, the hybrid cord comprising at least a first yarn having a first end and a second yarn having a second end, wherein the first end and the second end are twisted together, and wherein the proportion of the first yarn in the hybrid cord is 80-95% by weight and an asymmetry of the first yarn and the second yarn is based on a shallow initial region of a force/elongation curve;
 wherein the first yarn is a high-modulus yarn with a specified yarn fineness, wherein the second yarn being is a low-modulus yarn and having a lower yarn fineness than the first yarn, and wherein the yarn fineness of the first yarn in comparison with the yarn fineness of the second yarn is ≥800 dtex; 
 wherein the elongation at break of the first yarn lies in a range of 1%-8% and the elongation at break of the second yarn lies in a range of 9%-30%; and, 
 wherein the hybrid cord as has a construction of aramid 1680×2+nylon 700×1, or a construction of carbon fiber 1600×2+nylon 700×1; or, 
 wherein the hybrid cord as has a construction of aramid 1680×2+nylon 470×1, or a construction of carbon fiber 1600×2+nylon 470×1; or, 
 wherein the hybrid cord as has a construction of aramid 1680×2+nylon 235×1 or a construction of carbon fiber 1600×2+nylon 235×1.